LinkedIn post from an experience

Turns something you did or learned into a LinkedIn post that is specific, not cringe.

Write a LinkedIn post based on this experience: {{WHAT HAPPENED / WHAT I LEARNED}}.

Audience: {{WHO: e.g. founders, backend developers, recruiters}}.

Rules:
- First line: a specific, concrete hook (a number, a mistake, a result). No "I'm thrilled to announce".
- Tell what happened in 3-5 short paragraphs, with one real detail that only I would know.
- One lesson, stated plainly. Not five.
- End with a question that invites experienced people to answer.
- Under 200 words. No hashtag walls (2 max). No emojis as bullet points.

Give me 3 different opening lines to choose from.